Safety and Clinical Efficacy of Mesenchymal Stem Cell Treatment in Traumatic Spinal Cord Injury, Multiple Sclerosis and Ischemic Stroke - A Systematic Review and Meta-Analysis

Blood-brain barrier repair: potential and challenges of stem cells and exosomes in stroke treatment

Stroke is characterized with high morbidity, mortality and disability all over the world, and one of its core pathologies is blood-brain barrier (BBB) dysfunction. BBB plays a crucial physiological role in protecting brain tissues and maintaining homeostasis in central nervous system (CNS). BBB dysfunction serves as a key factor in the development of cerebral edema, inflammation, and further neurological damage in stroke patients. Currently, stem cells and their derived exosomes have shown remarkable potential in repairing the damaged BBB and improving neurological function after stroke. Stem cells repair the integrity of BBB through anti-inflammatory, antioxidant, angiogenesis and regulation of intercellular signaling mechanisms, while stem cell-derived exosomes, as natural nanocarriers, further enhance the therapeutic effect by carrying active substances such as proteins, RNAs and miRNAs. This review will present the latest research advances in stem cells and their exosomes in stroke treatment, as well as the challenges of cell source, transplantation timing, dosage, and route of administration in clinical application, aiming to discuss their mechanisms of repairing BBB integrity and potential for clinical application, and proposes future research directions. Stem cells and exosomes are expected to provide new strategies for early diagnosis and precise treatment of stroke, and promote breakthroughs in the field of stroke.

Drug Delivery Across the Blood-Brain Barrier: A New Strategy for the Treatment of Neurological Diseases

The blood-brain barrier (BBB) serves as a highly selective barrier between the blood and the central nervous system (CNS), and its main function is to protect the brain from foreign substances. This physiological property plays a crucial role in maintaining CNS homeostasis, but at the same time greatly limits the delivery of drug molecules to the CNS, thus posing a major challenge for the treatment of neurological diseases. Given that the high incidence and low cure rate of neurological diseases have become a global public health problem, the development of effective BBB penetration technologies is important for enhancing the efficiency of CNS drug delivery, reducing systemic toxicity, and improving the therapeutic outcomes of neurological diseases. This review describes the physiological and pathological properties of the BBB, as well as the current challenges of trans-BBB drug delivery, detailing the structural basis of the BBB and its role in CNS protection. Secondly, this paper reviews the drug delivery strategies for the BBB in recent years, including physical, biological and chemical approaches, as well as nanoparticle-based delivery technologies, and provides a comprehensive assessment of the effectiveness, advantages and limitations of these delivery strategies. It is hoped that the review in this paper will provide valuable references and inspiration for future researchers in therapeutic studies of neurological diseases.

Effects of multiple treatments with stem cell therapy in patients with multiple sclerosis

OBJECTIVE

This study was to evaluate the effectiveness of stem cell therapies (AHSCT: autologous hematopoietic stem cell transplantation and MSCs: mesenchymal stem cells) compared to non-stem cell therapies in multiple sclerosis (MS) patients.

DESIGN

Clinical trials to investigate the therapeutic effects of stem cells therapy was searched by PubMed, Embase, Web of Science, and the Cochrane Library. The Cochrane Risk of Bias Assessment Tool and data analysis software will be applied.

RESULTS

Data were collected between the earliest available date and August 2023. Ten studies were included, with a sample size of 5288 used in the studies. Results showed that human umbilical cord-derived mesenchymal stem cells reduced the Annualized Relapse Rate (SUCRA: 70.9 %) and Expanded Disability Status Scale (SUCRA: 77.1 %) of MS patients, AHSCT reduced mortality rate (SUCRA: 69.8 %), autologous peripheral blood stem cell transplantation (APBSCT) reduced recurrence rate (SUCRA: 86.7 %) and improved No Evidence of Disease Activity-3 (SUCRA: 92.8 %).

CONCLUSION

At present, AHSCT and MSCs have been demonstrated to reduce the recurrence rate of multiple sclerosis and improve disability, particularly in the case of hUC-MSCs. However, APBSCT and AHSCT in the context of the NEDA-3 criteria have not yielded the desired outcomes.

Adverse events of cell therapy clinical trials in human chronic spinal cord injury, a systematic review and meta-analysis

Spinal cord injury is a lesion with high mortality and significant morbidities. After the primary injury, during six months, a cascade of secondary cellular and molecular events makes the lesion chronic. Recently, cell-based clinical trials as a new procedure have been gradually tested to improve the symptoms of patients. Each treatment method is associated with different adverse events. Based on the PRISMA flow diagram of the identified records, and after multistep screening, finally in 76 reviewed studies with 1633 cases and 189 controls, 64 types of adverse events in 12 categories were recorded in 45 studies. The most common adverse events were transient backache and meningism (90%) and cord malacia (80%). The cell therapy method in which the treatment was associated with more adverse events was Olfactory ensheathing cell and bone marrow mesenchymal stem cell combination therapy in 55%, and the adverse events were less with the embryonic stem cell in 2.33% of patients. In a meta-analysis, the total prevalence of adverse events in cell therapy was 19% and the highest pulled effect size belonged to urinary tract and localized adverse events. Also, the total prevalence of adverse events in 14 cell therapy methods was 18% and four cell types (neural stem cell, bone marrow hematopoietic stem cell, embryonic stem cell, and umbilical cord mesenchymal stem cell) had the most effect. None of the adverse events were reported on the 4 (life-threatening consequences) and 5 (death) grading scales. We concluded that the frequency of life-threatening adverse events following cell therapy clinical trials in chronic spinal cord injury patients is very scarce and can be ignored.

Mesenchymal stromal cell therapies for traumatic neurological injuries

Improved treatment options are urgently needed for neurological injuries resulting from trauma or iatrogenic events causing long-term disabilities that severely impact patients' quality of life. In vitro and animal studies have provided promising proof-of-concept examples of regenerative therapies using mesenchymal stromal cells (MSC) for a wide range of pathological conditions. Over the previous decade, various MSC-based therapies have been investigated in clinical trials to treat traumatic neurological injuries. However, while the safety and feasibility of MSC treatments has been established, the patient outcomes in these studies have not demonstrated significant success in the translation of MSC regenerative therapy for the treatment of human brain and spinal cord injuries. Herein, we have reviewed the literature and ongoing registered trials on the application of MSC for the treatment of traumatic brain injury, traumatic spinal cord injury, and peripheral nerve injury. We have focused on the shortcomings and technological hurdles that must be overcome to further advance clinical research to phase 3 trials, and we discuss recent advancements that represent potential solutions to these obstacles to progress.

SHED-CM: The Safety and Efficacy of Conditioned Media from Human Exfoliated Deciduous Teeth Stem Cells in Amyotrophic Lateral Sclerosis Treatment: A Retrospective Cohort Analysis

BACKGROUND/OBJECTIVES

Amyotrophic lateral sclerosis (ALS) is a progressive and irreversible neurodegenerative disease with limited treatment options. Advances in regenerative medicine have opened up new treatment options. The primary and exploratory objectives of this retrospective cohort study were to evaluate the safety and efficacy of stem cells from human exfoliated deciduous teeth-conditioned media (SHED-CM).

METHODS

Safety assessments included adverse events, vital signs, and laboratory test changes before and after administration, and efficacy was measured using the ALS Functional Rating Scale-Revised (ALSFRS-R), grip strength, and forced vital capacity in 24 patients with ALS treated at a single facility between 1 January 2022, and 30 November 2023.

RESULTS

While ALSFRS-R scores typically decline over time, the progression rate in this cohort was slower, suggesting a potential delay in disease progression. Alternatively, improvements in muscle strength and mobility were observed in some patients. Although adverse events were reported in only 3% of cases (no serious allergic reactions), the treatment-induced changes in vital signs and laboratory results were not clinically significant.

CONCLUSIONS

The SHED-CM treatment is a safe and potentially effective therapeutic option for patients with ALS. Further research is needed to optimize the SHED-CM treatment; however, this study lays the groundwork for future exploration of regenerative therapies for ALS.

Mesenchymal stem cells in autoimmune disease: A systematic review and meta-analysis of pre-clinical studies

Mesenchymal Stem Cells (MSCs) are of interest in the clinic because of their immunomodulation capabilities, capacity to act upstream of inflammation, and ability to sense metabolic environments. In standard physiologic conditions, they play a role in maintaining the homeostasis of tissues and organs; however, there is evidence that they can contribute to some autoimmune diseases. Gaining a deeper understanding of the factors that transition MSCs from their physiological function to a pathological role in their native environment, and elucidating mechanisms that reduce their therapeutic relevance in regenerative medicine, is essential. We conducted a Systematic Review and Meta-Analysis of human MSCs in preclinical studies of autoimmune disease, evaluating 60 studies that included 845 patient samples and 571 control samples. MSCs from any tissue source were included, and the study was limited to four autoimmune diseases: multiple sclerosis, rheumatoid arthritis, systemic sclerosis, and lupus. We developed a novel Risk of Bias tool to determine study quality for in vitro studies. Using the International Society for Cell & Gene Therapy's criteria to define an MSC, most studies reported no difference in morphology, adhesion, cell surface markers, or differentiation into bone, fat, or cartilage when comparing control and autoimmune MSCs. However, there were reported differences in proliferation. Additionally, 308 biomolecules were differentially expressed, and the abilities to migrate, invade, and form capillaries were decreased. The findings from this study could help to explain the pathogenic mechanisms of autoimmune disease and potentially lead to improved MSC-based therapeutic applications.

Neurological efficacy and safety of mesenchymal stem cells (MSCs) therapy in people with multiple sclerosis (pwMS): An updated systematic review and meta-analysis

BACKGROUND

Current therapeutic strategies for multiple sclerosis (MS) aim to suppress the immune response and reduce relapse rates. As alternative treatments, mesenchymal stem cells (MSCs) are being explored. MSCs show promise in repairing nerve tissue and reducing autoimmune responses in people with MS (pwMS).

OBJECTIVE

This review delves into the literature on the efficacy and safety of MSC therapy for pwMS.

METHODS

A comprehensive search strategy was employed to identify relevant articles from five databases until January 2024. The inclusion criteria encompassed interventional studies. Efficacy and safety data concerning MSC therapy in relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and primary progressive MS (PPMS) groups were extracted and analyzed.

RESULTS

A comprehensive analysis encompassing 30 studies revealed that individuals who underwent intrathecal (IT) protocol-based transplantation of MSCs experienced a noteworthy improvement in their expanded disability status scale (EDSS) compared to the placebo group. Weighted mean difference (WMD) was -0.28; 95 % CI -0.53 to -0.03, I2 = 0 %, p-value = 0.028); however, the intravenous (IV) group did not show significant changes in EDSS scores. The annualized relapse rate (ARR) did not significantly decrease among pwMS (WMD = -0.34; 95 % CI -1.05 to 0.38, I2 = 98 %, p-value = 0.357). Favorable results were observed in magnetic resonance imaging (MRI), with only 19.11 % of pwMS showing contrast-enhanced lesions (CEL) in the short term and no long-term MRI activity. The most common complications in both short-term and long-term follow-ups were infection, back pain, and gastrointestinal symptoms.

CONCLUSIONS

The study highlights the safety potential of MSC therapy for pwMS. While MRI-based neural regeneration shows significant treatment potential, the effectiveness of MSC therapy remains uncertain due to study limitations and ineffective outcome measures. Further research is needed to establish efficacy and optimize evaluation methods for MSC therapy on pwMS.

Neural regeneration in the human central nervous system-from understanding the underlying mechanisms to developing treatments. Where do we stand today?

Mature neurons in the human central nervous system (CNS) fail to regenerate after injuries. This is a common denominator across different aetiologies, including multiple sclerosis, spinal cord injury and ischemic stroke. The lack of regeneration leads to permanent functional deficits with a substantial impact on patient quality of life, representing a significant socioeconomic burden worldwide. Great efforts have been made to decipher the responsible mechanisms and we now know that potent intra- and extracellular barriers prevent axonal repair. This knowledge has resulted in numerous clinical trials, aiming to promote neuroregeneration through different approaches. Here, we summarize the current understanding of the causes to the poor regeneration within the human CNS. We also review the results of the treatment attempts that have been translated into clinical trials so far.

BMP9 induces osteogenic differentiation through up-regulating LGR4 via the mTORC1/Stat3 pathway in mesenchymal stem cells

Bone defects and non-union are prevalent in clinical orthopedy, and the outcomes of current treatments are often suboptimal. Bone tissue engineering offers a promising approach to treating these conditions effectively. Bone morphogenetic protein 9 (BMP9) can commit mesenchymal stem cells to osteogenic lineage, and a knowledge of the underlying mechanisms may help advance the field of bone tissue engineering. Leucine-rich repeats containing G protein-coupled receptor 4 (LGR4), a member of G protein-coupled receptors, is essential for modulating bone development. This study is aimed at investigating the impact of LGR4 on BMP9-induced osteogenesis in mesenchymal stem cells as well as the underlying mechanisms. Bone marrow stromal cells from BMP9-knockout mice exhibited diminished LGR4 expression, and exogenous LGR4 clearly restored the impaired osteogenic potency of the bone marrow stromal cells. Furthermore, LGR4 expression was increased by BMP9 in C3H10T1/2 cells. LGR4 augmented the benefits of BMP9-induced osteogenic markers and bone formation, whereas LGR4 inhibition restricted these effects. Meanwhile, the BMP9-induced lipogenic markers were increased by LGR4 inhibition. The protein levels of Raptor and p-Stat3 were elevated by BMP9. Raptor knockdown or p-Stat3 suppression attenuated the osteoblastic markers and LGR4 expression brought on by BMP9. LGR4 significantly reversed the blocking effect of Raptor knockdown or p-Stat3 suppression on the BMP9-induced osteoblastic markers. Raptor interacts with p-Stat3, and p-Stat3 activates the LGR4 promoter activity. In conclusion, LGR4 boosts BMP9 osteoblastic potency in mesenchymal stem cells, and BMP9 may up-regulate LGR4 via the mTORC1/Stat3 signal activation.

Wound healing potential of Cystoseira/mesenchymal stem cells in immunosuppressed rats supported by overwhelming immuno-inflammatory crosstalk

Wound healing, one of the most intricate and dynamic processes of the body, maintains skin integrity following trauma. One of the main issues that still exists is impaired wound healing, particularly for immunosuppressed patients. Recently, natural products from marine environments have been employed in wound-repairing activities. This work investigates the mesenchymal stem cells in the combined capacity of the bone marrow (BMMSC) for wound healing and Cystoseira sp. Algae extract in immunosuppressed rats. High-resolution liquid chromatography / MS investigation of Cystoseira extract revealed the prevalence of fatty acids that have wound-soothing potential. From constructed PPI network for wound healing and further analysis through molecular docking and molecular dynamics (MD) simulation experiments suggested that cystalgerone metabolite may be responsible for the wound healing-promoting effect of Cystoseira extract. According to the CD marker characterization of the BMMSC, 98.21% of them expressed CD90, and 97.1% expressed CD105. Sixteen d after immunity suppression (by 40 mg/kg hydrocortisone daily), an incision was made in the dorsal skin of the rat. The treatments were applied for 16 d and samples were taken from the tested groups on the 8th, 14th, and 16th days. The BMMSCs / Cystoseira group showed significantly improved wound closure, thickness, density of new layers, and skin elasticity than the control group (p < 0.001). The BMMSCs / Cystoseira combination significantly reduced the oxidative indicators, pro-inflammatory cytokines, and immune markers, according to the RT-PCR gene expression study. In order to delve deeper into the complex interconnections among wound healing-related biological targets and pinpoint key factors in this complex process, we engaged in network pharmacology and computational research. Subsequently, we conducted a comprehensive computational analysis, including reverse docking, free energy (ΔG) computation, and molecular dynamics simulations, on the molecular structures of the annotated compounds. The purpose of this investigation was to identify potential new targets for these chemicals as well as any potential interactions they may have with different signaling pathways related to the wound healing process. Our research indicates that the primary compounds of Cystoseira holds potential wound healing therapeutic activity. Although more safety testing and clinical studies are required, the combination has great potential for regenerative medicine and could be a revolutionary advance in the healing of the wounds of immunosuppressed patients.

Systematic Review of Cell Therapy Efficacy in Human Chronic Spinal Cord Injury

Spinal cord injury (SCI) is one of the most debilitating problems for humans. About 6 months after the initial injury, a cascade of secondary cellular and molecular events occurs and the primary damage enters the chronic phase. Current treatments are not curative. One of the new treatment methods is the use of cell therapy, which is gradually being tested in clinical trials to improve the symptoms of SCI patients. In this review article, we investigated the effect of different cell therapy trials in improving patients' symptoms and their paraclinical indicators. In the 72 final reviewed studies with 1144 cases and 186 controls, 20 scores were recorded as outcomes. We categorized the scores into seven groups. In upper extremity motor score, daily living function, trunk stability, postural hypotension, somatosensory evoked potential, and motor evoked potential scores, the bone marrow hematopoietic stem cell therapy had a more healing effect. In the International Association of Neurorestoratology SCI Functional Rating Scale, light touch score, bowel function, decreased spasticity, Visual Analog Scale, and electromyography scores, the bone marrow mesenchymal stem cell had more impact. The olfactory ensheathing cell had a greater effect on lower extremity motor score and pinprick scores than other cells. The embryonic stem cell had the greatest effect in improving the important score of the American Spinal Injury Association scale. Based on the obtained results, it seems that a special cell should be used to improve each symptom of patients with chronic SCI, and if the improvement of several harms is involved, the combination of cells may be effective. Impact statement Compared to similar review articles published so far, we reviewed the largest number of published articles, and so the largest number of cases and controls, and the variety of cells we examined was more than other published articles. We concluded that different cells are effective for improving the symptoms and paraclinical indicators of patients with chronic spinal cord injury. Bone marrow hematopoietic stem cell and bone marrow mesenchymal stem cell have had the higher overall mean effect in more scores (each in six scores). If the improvement of several harms is involved, the combination of cells may be effective.

Mesenchymal stem cells and their extracellular vesicles as emerging therapeutic tools in the treatment of ischemic stroke

Ischemic stroke (IS) is a neurological condition characterized by severe long-term consequences and an unfavorable prognosis for numerous patients. Despite advancements in stroke treatment, existing therapeutic approaches possess certain limitations. However, accumulating evidence suggests that mesenchymal stem/stromal cells (MSCs) hold promise as a potential therapy for various neurological disorders, including IS, owing to their advantageous properties, such as immunomodulation and tissue regeneration. Additionally, MSCs primarily exert their therapeutic effects through the release of extracellular vesicles (EVs), highlighting the significance of their paracrine activities. These EVs are small double-layered phospholipid membrane vesicles, carrying a diverse cargo of proteins, lipids, and miRNAs that enable effective cell-to-cell communication. Notably, EVs have emerged as attractive substitutes for stem cell therapy due to their reduced immunogenicity, lower tumorigenic potential, and ease of administration and handling. Hence, this review summarizes the current preclinical and clinical studies performed to investigate the safety and therapeutic potential of MSCs and their EVs derived from different sources, including bone marrow, adipose tissue, umbilical cord blood, and Wharton's jelly in IS.

Translation of cell therapies to treat autoimmune disorders

Autoimmune diseases are a diverse and complex set of chronic disorders with a substantial impact on patient quality of life and a significant global healthcare burden. Current approaches to autoimmune disease treatment comprise broadly acting immunosuppressive drugs that lack disease specificity, possess limited efficacy, and confer undesirable side effects. Additionally, there are limited treatments available to restore organs and tissues damaged during the course of autoimmune disease progression. Cell therapies are an emergent area of therapeutics with the potential to address both autoimmune disease immune dysfunction as well as autoimmune disease-damaged tissue and organ systems. In this review, we discuss the pathogenesis of common autoimmune disorders and the state-of-the-art in cell therapy approaches to (1) regenerate or replace autoimmune disease-damaged tissue and (2) eliminate pathological immune responses in autoimmunity. Finally, we discuss critical considerations for the translation of cell products to the clinic.

Improved Efficacy of Delayed Treatment with Human Bone Marrow-Derived Stromal Cells Evaluated in Rats with Spinal Cord Injury

The treatment of spinal cord injury (SCI) with uncultivated human bone marrow-derived stromal cells (bmSCs) prepared by negative selection has been proposed to be therapeutically superior to treatment with stem cells that were expanded in vitro. To explore their use in clinical trials, we studied the functional effects of delayed application at 7 days after SCI by testing different doses of bmSCs. Spinal cord contusion injury was induced in adult male Wistar rats at the thoracic level T9. Human bmSCs were prepared by negative selection without expansion in vitro (NeuroCellsTM). Treatment consisted of one 150 µL injection into the cisterna magna containing 0.5 or 2.5 million fresh bmSCs or 2.5 million bmSCs. The recovery of motor functions was evaluated during a surveillance period of six weeks (6 W), during which spinal cords were assessed histologically. Treatment resulted in a significant, dose-dependent therapeutic effect on the recovery of motor performance. The histological analysis revealed a lower degree of axonal degeneration and better survival of neurons and oligodendrocytes in bmSCs treated rats. Our results support delayed intrathecal application of bmSCs prepared by negative selection without expansion in vitro as a treatment of SCI.

Mechanisms of Stem Cells and Their Secreted Exosomes in the Treatment of Autoimmune Diseases

Stem cells play a therapeutic role in many diseases by virtue of their strong self-renewal and differentiation abilities, especially in the treatment of autoimmune diseases. At present, the mechanism of the stem cell treatment of autoimmune diseases mainly relies on their immune regulation ability, regulating the number and function of auxiliary cells, anti-inflammatory factors and proinflammatory factors in patients to reduce inflammation. On the other hand, the stem cell- derived secretory body has weak immunogenicity and low molecular weight, can target the site of injury, and can extend the length of its active time in the patient after combining it with the composite material. Therefore, the role of secretory bodies in the stem cell treatment of autoimmune diseases is increasingly important.

The role of primed and non-primed MSC-derived conditioned media in neuroregeneration

Introduction

With growing significance in nervous system repair, mesenchymal stem cell-derived conditioned media (MSCCM) have been used in cell-free therapies in regenerative medicine. However, the immunomodulatory and neuroregenerative effects of MSCCM and the influence of priming on these effects are still poorly understood.

Methods

In this study, by various methods focused on cell viability, proliferation, neuron-like differentiation, neurite outgrowth, cell migration and regrowth, we demonstrated that MSCCM derived from adipose tissue (AT-MSCCM) and amniotic membrane (AM-MSCCM) had different effects on SH-SY5Y cells.

Results and discussion

AT-MSCCM was found to have a higher proliferative capacity and the ability to impact neurite outgrowth during differentiation, while AM-MSCCM showed more pronounced immunomodulatory activity, migration, and re-growth of SH-SY5Y cells in the scratch model. Furthermore, priming of MSC with pro-inflammatory cytokine (IFN-γ) resulted in different proteomic profiles of conditioned media from both sources, which had the highest effect on SH-SY5Y proliferation and neurite outgrowth in terms of the length of neurites (pAT-MSCCM) compared to the control group (DMEM). Altogether, our results highlight the potential of primed and non-primed MSCCM as a therapeutic tool for neurodegenerative diseases, although some differences must be considered.

Novel Therapeutic Opportunities for Neurodegenerative Diseases with Mesenchymal Stem Cells: The Focus on Modulating the Blood-Brain Barrier

Neurodegenerative disorders encompass a broad spectrum of profoundly disabling situations that impact millions of individuals globally. While their underlying causes and pathophysiology display considerable diversity and remain incompletely understood, a mounting body of evidence indicates that the disruption of blood-brain barrier (BBB) permeability, resulting in brain damage and neuroinflammation, is a common feature among them. Consequently, targeting the BBB has emerged as an innovative therapeutic strategy for addressing neurological disorders. Within this review, we not only explore the neuroprotective, neurotrophic, and immunomodulatory benefits of mesenchymal stem cells (MSCs) in combating neurodegeneration but also delve into their recent role in modulating the BBB. We will investigate the cellular and molecular mechanisms through which MSC treatment impacts primary age-related neurological conditions like Alzheimer's disease, Parkinson's disease, and stroke, as well as immune-mediated diseases such as multiple sclerosis. Our focus will center on how MSCs participate in the modulation of cell transporters, matrix remodeling, stabilization of cell-junction components, and restoration of BBB network integrity in these pathological contexts.

Mesenchymal Stem Cell Therapy in Traumatic Spinal Cord Injury: A Systematic Review

Recovery from a traumatic spinal cord injury (TSCI) is challenging due to the limited regenerative capacity of the central nervous system to restore cells, myelin, and neural connections. Cell therapy, particularly with mesenchymal stem cells (MSCs), holds significant promise for TSCI treatment. This systematic review aims to analyze the efficacy, safety, and therapeutic potential of MSC-based cell therapies in TSCI. A comprehensive search of PUBMED and COCHRANE databases until February 2023 was conducted, combining terms such as "spinal cord injury," "stem cells," "stem cell therapy," "mesenchymal stem cells," and "traumatic spinal cord injury". Among the 53 studies initially identified, 22 (21 clinical trials and 1 case series) were included. Findings from these studies consistently demonstrate improvements in AIS (ASIA Impairment Scale) grades, sensory scores, and, to a lesser extent, motor scores. Meta-analyses further support these positive outcomes. MSC-based therapies have shown short- and medium-term safety, as indicated by the absence of significant adverse events within the studied timeframe. However, caution is required when drawing generalized recommendations due to the limited scientific evidence available. Further research is needed to elucidate the long-term safety and clinical implications of these advancements. Although significant progress has been made, particularly with MSC-based therapies, additional studies exploring other potential future therapies such as gene therapies, neurostimulation techniques, and tissue engineering approaches are essential for a comprehensive understanding of the evolving TSCI treatment landscape.

Research hotspots and frotiers of stem cells in stroke: A bibliometric analysis from 2004 to 2022

Background: Stroke is one of the leading causes of mortality and permanent disability worldwide. However, the current stroke treatment has a limited effect. Therefore, a new treatment is urgently needed. Stem cell therapy is a cutting-edge treatment for stroke patients. This study aimed to gain better understanding of global stem cell trends in stroke via a bibliometric analysis. Methods: We used the Web of Science Core Collection to search pertinent articles about stem cells in stroke published between 2004 and 2022. Analysis was conducted using CiteSpace, VOSviewer, and the R package "bibliometrix" to identify publication outputs, countries/regions, institutions, authors/co-cited authors, journals/co-cited journals, co-cited references, and keywords. Results: A total of 6,703 publications were included in the bibliometric analysis. The total number of citations significantly and rapidly increased between 2004 and 2022, with the most pronounced growth pattern observed in the period of 2008-2009. In terms of authoritarian countries, the USA had the most publications among the countries. As for institutions and authors, the most prolific institution was the University of South Florida, followed by Oakland University and then Shanghai Jiao Tong University, and Chopp, M. and Borlongan, Cesario V, had the most output among the authors. Regarding the journals, Cell Transplantation had the highest publication, followed by Brain Research. As for references, "Mesenchymal stem cells as trophic mediators" was the most frequently cited (2,082), and the article entitled Neuronal replacement from endogenous precursors in the adult brain after stroke had the strongest burstiness (strength = 81.35). Emerging hot words in the past decade included "adhesion molecule," "mesenchymal stromal cell," "extracellular vesicle," "pluripotent stem cells," "signaling pathway," "plasticity," and "exosomes." Conclusion: Between 2004 and 2022, the terms "neurogenesis," "angiogenesis," "mesenchymal stem cells," "extracellular vesicle," "exosomes," "inflammation," and "oxidative stress" have emerged as the hot research areas for research on stem cells in stroke. Although stem cells exert a number of positive effects, the main mechanisms for mitigating the damage caused by stroke are still unknown. Clinical challenges may include complicating factors that can affect the efficacy of stem cell therapy, which are worth a deep exploration.

Autologous Stem Cells Transplants in the Treatment of Temporomandibular Joints Disorders: A Systematic Review and Meta-Analysis of Clinical Trials

This systematic review aims to analyze the outcomes of the treatment of temporomandibular joint (TMJ) articular pain (AP) and restricted maximum mouth opening (MMO) with intra-articular administration of mesenchymal stem cells (MSCs). The inclusion criteria allowed primary studies involving AP and/or MMO pre-treatment and post-intervention values. Medical databases that were covered by ACM Digital, BASE, EBSCOhost, Google Scholar, PubMed, Scopus, and Web of Science engines were searched. The risk of bias was assessed with RoB 2 and ROBINS-I tools. The results were tabulated, plotted, and analyzed for regression. A total of 5 studies involving 51 patients/69 TMJs were identified, and 4 studies on 50 patients/67 TMJs were synthesized. Interventions were each time effective in decreasing AP and increasing MMO in a 6-month follow-up period by an average of about 85% and over 40%, respectively. Regression analysis showed a good fit of the logarithmic model for AP relief (5.8 − 0.8 ln x; R² = 0.90) and MMO increase (33.5 + 2.4 ln x; R² = 0.89). The results for AP and MMO were based on 3 studies in 39 patients and 4 studies in 50 patients, respectively, all at high risk of bias. The intra-articular administration of MSCs to TMJs, based on weak evidence, may be highly effective in reducing AP and improving MMO. This study received no funding.